As I promised, here it is! This can be modified to "fit" other transmission models in other models of Panthers with very little thought...
(Mods, someone want to sticky this so it can be in the back of peoples' heads as they fight with hard-to-adjust AODs?)

Before you read on: References to "Panthers" are references to the chassis. The Crown Victoria / Grand Marquis / Town Car platforms are referred to as Panther chassis, much like the 80s Mustangs were known as Fox chassis.

I could never get my AOD adjusted quite right, so I finally gave up. I started researching and gathering parts, and here is what I came up with:

I removed the AOD and all the related equipment (transmission, shifter equipment, flywheel). I then installed the following parts:

From there, I took the clutch pedal assembly from a manual Fox Mustang (1983 GT Turbo in my case) and chopped it into a stock Crown Victoria brake pedal assembly...

The pedal assembly on the 1990+ Panthers will be very different. You can weld the pedal shaft tube to the front edge of the assembly and it will work (test fit first!), but you'll still need to modify the clutch pedal itself so it can clear the floorboard.

You will need to cut a notch into the channel on the under side of your dashboard so the clutch quadrant can clear. It's not that difficult, but trust me- HAVE A SPRAY BOTTLE FULL OF WATER HANDY FOR WHEN THE INSULATION AROUND IT DECIDES TO IGNITE. It WILL happen.

Here you can see the notch I cut into the dash channel to clear the quadrant.

To get the clearance on the firewall for the clutch cable, I had to use a 1992+ Panther brake booster because they are significantly smaller in diameter. With the new booster comes the requirement of a new master cylinder because the bolts on the booster are too wide for the older cylinder.

Once the pedal assembly is built, make a template. To do this, put the assembly on a flat piece of cardboard. Mark the four bolt holes and take a straight edge and mark straight down from the channel of the clutch quadrant. Then align the bolt holes on the template with the holes in the firewall and mark to drill a hole for your clutch cable.

So, the pedal assembly and cable are ready, but now what?

When installing the transmission, remember to use shorter bolts from a T5 Mustang or cut 1/2" off the AOD bolts, since they'll be too long otherwise. For the shifter, just get the transmission into place and cut the hole large enough to leave 1/2" on every side of the shifter plate (the plate WILL come level with the floorboard) so there is room when the transmission and shifter torque to the side during "spirited" driving.

If you're using a pre-1990 Panther, you need to drill new transmission crossmember holes 1" in front of the rear holes on your stock crossmember mounting brackets (which are located on the framerails). This is the ONLY way it will fit. You will also need to use a driveshaft from a 1990+ Panther because the stock driveshaft is too long. To fit the newer driveshaft, you also need the pinion flange from the newer Panther.

This is why the newer shaft won't fit the older pinion flange- the bolt pattern is significantly larger and the old flange can't even be drilled to work.

For 1990+ Panthers, you can either stretch the crossmember mounting holes forward 1/2" or you can squeeze things together by hand-threading all the bolts to start and torque them down, allowing the rubber mount to stretch to compensate for the difference.

As for the wiring:
There is a four-wire harness that plugged into the front of your AOD. That controlled the neutral safety switch and the reverse lights. The easiest way to figure out which did what is to touch two of them together at a time. When the reverse lights come on, those are the wires to use. Take one of those and put it on one of the pigtail connectors on the driver's side of the T5 and put the other on the other side. It's a simple switch, so it doesn't matter which side gets which wire. For the other two, you can either route them to your clutch pedal and build a neutral safety switch so the car won't start without the clutch being engaged or you can permanently attach the two. I attached the two.

A grand total of the parts needed for the conversion:

T5 Manual transmission (302-specific is best)
Clutch, pressure plate, etc kit
Pilot bearing for 302 Mustang
Flywheel for 302 Mustang (Make sure it matches the bellhousing [you don't want to try to install a 10.5" disc flywheel into a 10" disc bellhousing])
Shifter assembly (run a stock piece until you get the feel for it and modify as you please. Most prefer to run a tall, truck-style shifter)
Shifter boot
Two upper bellhousing bolts from a T5 Mustang (the AOD bolts are 1/2" too long)

NEW INFORMATION: (only read on if you have a 1989 or older Panther) the yoke on a 4R70W transmission has a different spline count from the AOD/T5, so one would need the earlier yoke in order for the driveshaft from a 1992+ Panther to work. It's also about 1.5-2" longer than the earlier yoke.

Also, the pinion flange adapter has the larger design, so on a 1989 or older, one would need to swap the pinion flange adapter, too, using the following joint:

Spicer Part #: 5-134X
Precision Joint #: 353

They're the same thing, just different companies. Auto parts stores can cross reference those numbers to find the joint made by the company they use. O'Reilly uses Precision Joint.

It's not the first choice people would make for a performance enhancement, but it's a GREAT choice in place of an AOD replacement.
My AOD was blown and the local shop wanted $1800 just for the transmission. I could have had an AOD built with performance bands and clutches from another shop for $1200, but I'd still only have the stock hard parts. I spent $700 (TOTAL!) on this entire swap and I'll never need to fight with the TV adjustments, again.

This looks like a great conversion, and one that I'd like to do when I get time (or at least dream about doing). I'm wondering what the range of years of Mustangs is that I can get this setup from. I know the transmission itself isn't a big deal, but what year did they use the cable clutch?

All Fox bodies had the cable clutch. I did this entire swap for under $750. Don't feel like it's that expensive. If I can recommend anything, it's to find a transmission from a 1989 or newer Mustang; they're rated for 300lb/ft, while the one I'm running is rated for 265lb/ft. Oh, well- great excuse for a TKO.

Hey man nice work and thats all very useful information, ive been wanting to put a T5 in my Vic for awhile now, but everytime i go junkyard shopping no one wants to sell anything, but im gonna keep trying. Id love to see some pics of this monster when its all said and done, well good luck.

Thanks, Chris. I can't take the credit, though. A guy named Steve did it initially, on his 1990 Crown Victoria. I took his information and did it myself, but ran into a snag on... well... everything. Every part that had to be modified or was a questionable fit was different between the 89 and 90 models.
I tried to use pictures of his pedal assembly in this post, but it didn't work right. What year is yours?

Mine is a 1991 Crown Victoria LTD. I just recently did some work to it...i put a cage back in it gutted out the interior, repaired the rust holes in the floor, some new seats and a little interior customization....id love to do a t5 swap someday but everytime i find a 5 speed on the internet the price is way to high or no one wants to sell anything...but someday itll be done...im takin some pictures tonight ill post them up as soon as possible...

My build didn't last too long. I already parted it out. I was having problems with the electrical system and it was getting to the point where I'd have had to build or buy a whole new wiring harness which I didn't feel like doing. Just before a 1-2 shift on the way home from lunch a couple months ago I snapped the ring gear in the differential. I took that as a lesson and started pulling everything out of it. It was a fun build, but the new Panther is an automatic since I'll be towing my 4x4 with it.